People love to hate on airlock watching, but in this case it's actually working as an indicator. It's indicating that the OP's primary fermentation is done or almost done. Since you plans to use a secondary anyways then go ahead and rack it over now.

The next steps are correct, but the campden will not stop the yeast from eating any sugars you add as backsweeteners. For instructions on how to have a sweet, sparkling cider I suggest you read through the pasteurization sticky at the top of the cider section.

So what you're saying is that the airlock is indicating the fermentation either is or is not complete? I wish I had a job with that sort of success rate.

Since the OP reported the bubbles slowing significantly AND it's been 3 weeks it's a pretty sure bet that things are wrapping up in there. Just airlock or just time would be insufficient to make such a call.

__________________In all the states no door stands wider,
To ask you in to drink hard cider

These tips have been extremely valuable and greatly appreciated! The day I started the batch I also found out my wife was pregnant. I thought it'd be rather "neat" to have a nice bottle around to commemorate. I'd rather do that with good cider than bad

I'll be looking into the benefits of secondary fermentation to see if that's the route I want to take -or- if I should just begin the pasturizing / bottling process now.